Proposals being considered including deploying troops to Eastern Europe under direct Nato command in peacetime, in an unprecedented move that will likely be greeted with fury in Moscow, according to diplomats and military officials interviewed by the Wall Street Journal.

One plan reportedly under consideration would see battalions of 800 to 1,000 troops deployed to Poland, Lithuania, Latvia, and Estonia. A less extensive plan would see a single battalion deployed to the region.

File photo: Members of the Russian armed forces stand guard around the Ukrainian military base in the village of Perevalne, Crimea Photo: PA

Diplomats and military chiefs are believed to be keen to “send a message” to Moscow that the alliance is well coordinated and committed to defending its eastern most member states.

Several eastern members including Poland, Estonia, Lithuania, and Latvia, have called for a significant strengthening of the alliance’s military presence to the region to deter possible Russian aggression.

But others, notably Germany, are said to be wary of making a large deployment that could provoke a response from Russia when the ceasefire in Ukraine appears to be holding.

Russia has repeatedly said it considers Nato a security threat, and Vladimir Putin has blamed the expansion of Nato into Eastern Europe for the crisis in Ukraine.

A large force would likely be seen in Moscow as a violation of a 1994 agreement that forbids the deployment of “substantial” units to frontier areas. Nato has repeatedly accused Russia of violating that agreement but insists that it has kept to it.

A Nato spokesman said Nato has already bolstered its eastern defences with the creation of a rotational force and six small headquarters in the region, as well as an intensive program of exercises.

File photo: Members of the Russian armed forces stand guard around the Ukrainian military base in the village of Perevalne, Crimea Photo: PA

“Allies will continue to discuss the next steps to deal with security challenges as we prepare for NATO summit in Warsaw next July, including how to further strengthen collective defence through long-term adaption. But we are not discussing at this stage specific options,” said Carmen Romero, a Nato deputy spokesperson.

"It would be designed to communicate to the Russians that Nato is serious: it will defend Nato territory"

Steven Pfifer, former US Ambassador

Maria Zakharova, a spokesman for the Russian foreign ministry, said Russian officials would study the reports before issuing a public response.

Steven Pfifer, a former US Ambassador to Ukraine and senior fellow at the Brookings Institution, said the fact that such discussions were even taking place was an indication that Nato now viewed Russia "not as the partner we'd hoped for over the past 20-odd years, but more as a potential adversary. You're starting to turn the ship."

"If you're talking 800 to 1,000 troops, that would be big," he added. "And it would be designed to communicate to the Russians that Nato is serious: it will defend Nato territory."

File photo: Members of the Russian armed forces stand guard around the Ukrainian military base in the village of Perevalne, Crimea Photo: PA

Mr Pfifer said that Russia would "not welcome" any troop increases, but that the response from Moscow would depend on the types of troops deployed.

"I wouldn't put an armoured brigade in Eastern Estonia. I think that would be very provocative. But you could do other types of forces that would really not have the capability to head off and take St Petersburg."

Mr Pfifer said that if Nato "puts that marker down to the Russians" by discussing significant troop increases, it would send "mixed messages" should they fail to follow through.